There are many kinds of vending machines, where the goods are made available upon a payment being made. The most common ones are the coin-in a slot machines, which, however, suffer from certain disadvantages. On the one hand they are expensive to manufacture and, it is often, difficult to combine the price of the goods with the kind of coin suitable for the machine, and furthermore the accumulation of coins in a machine, which is not regularly watched, will always be a temptation to burglary.